Leptospirosis presenting as acute encephalitis syndrome (AES) in Assam, India

To establish leptospirosis as a new aetiology of the patients presenting acute encephalitis syndrome (AES). Japanese encephalitis, West Nile, Dengue and Chikungunya negative samples were tested by IgM capture ELISA for leptospira specific IgM. For further confirmation, the IgM positive samples were subjected to Microscopic agglutination test (MAT). The clinical details and laboratory findings of the positive patients were recorded. We report 8 cases of leptospirosis presenting as AES, proven on IgM capture ELISA and confirmed by MAT. Fever (100%) and altered sensorium (62.5%) were two most common symptoms. Low haemoglobin (7.5 ± 2.8) g/dL, elevated blood urea (79.16 ± 46.43) mg/dL, serum creatinine (1.5 ±1.2) mg/dL, SGOT (66.5 ± 14.84) U/L and SGPT (70.5 ± 4.9) U/L were observed in positive patients. This is the maiden study reporting leptospirosis as a new aetiology of the patients presenting AES. Establishing aetiology is very important for a successful therapy at least in treatable conditions like leptospirosis.